A conventional High Vertical Alignment (HVA) pixel electrode is structured in form of fine slits, in which a slit portion is provided with no pixel electrode and thus presents a relatively poor control over an electric field and furthermore a relatively poor control over liquid crystal molecules. As a result, dark fringes would occur in this portion, causing loss of liquid crystal efficiency and hence loss of transmittance of a liquid crystal display panel. In order to improve the transmittance of the liquid crystal display panel, proposed is a new pixel electrode having a three-dimensional structure. The three-dimensional pixel electrode covers an opening area of a pixel unit.
During manufacture of an array substrate having the aforementioned three-dimensional pixel electrode, a contact hole and an insulation layer in the three-dimensional pixel electrode are usually etched simultaneously. That is, one mask plate is used for forming both the contact hole and the three-dimensional structure of the pixel electrode at the same time. As such, the costs of the mask plate and processing time can be effectively saved. However, a portion of the insulation layer in the three-dimensional pixel electrode will be entirely etched away. If, at this time, a shielding electrode is added in order to improve the aperture ratio of the liquid crystal display panel, the shielding electrode might contact the pixel electrode. Therefore, addition of a shielding electrode is impossible in this case, and the aperture ratio of the liquid crystal display panel would be reduced.
In view of the above, there is an urgent need of a mask plate that can both form a three-dimensional pixel electrode and improve the aperture ratio of the liquid crystal display panel, a method for manufacturing a corresponding array substrate, and an array substrate.